Mail sent to comcast recipients silently discarded (no error, not sent to spam/junk)?

Have had this exact problem since about 5 August.  Am using Outlook in Office 365 and have tried all sorts of different settings.  None solve the problem.

---

@prest1gtm wrote:

Just started happening yesterday - email sent to recipients with @comcast.com domains are being silently discarded or not forwarded to recipients.  Sending domain's mail server is not on Comcast's network, was working fine for years until yesterday. 

 

No bounce, no error, sending mail server logs show the email was accepted by comcast. But recipients do not have it - not even in junk mail.   Sending domain and IP address are not on any known block lists and mail server security certificates/DKIM/etc are up to date.

 

Anyone else have this problem? 

---

Do you mean @comcast.net instead of @comcast.com?